package org.jeecg.modules.online.config.dialect;

import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;
import org.hibernate.type.StandardBasicTypes;

import java.sql.Types;

/**
 *  SQLite 方言
 */
public final class  SQLiteDialect extends Dialect {

    public SQLiteDialect(){
        registerColumnType(Types.NULL, "null");

        registerColumnType(Types.BIT, "integer");
        registerColumnType(Types.TINYINT, "integer");
        registerColumnType(Types.SMALLINT, "integer");
        registerColumnType(Types.INTEGER, "integer");
        registerColumnType(Types.BIGINT, "integer");
        registerColumnType(Types.BOOLEAN, "integer");

        registerColumnType(Types.REAL, "real");
        registerColumnType(Types.DOUBLE, "real");
        registerColumnType(Types.FLOAT, "real");
        registerColumnType(Types.NUMERIC, "numeric");
        registerColumnType(Types.DECIMAL, "numeric");

        registerColumnType(Types.CHAR, "text");
        registerColumnType(Types.VARCHAR, "text");
        registerColumnType(Types.CLOB, "text");
        registerColumnType(Types.LONGVARCHAR, "text");

        registerColumnType(Types.BLOB, "blob");
        registerColumnType(Types.CLOB, "clob");

        registerColumnType(Types.DATE, "date");
        registerColumnType(Types.TIMESTAMP, "datetime");


        registerFunction("concat", new VarArgsSQLFunction(StandardBasicTypes.STRING, "", "||", ""));
        registerFunction("mod", new SQLFunctionTemplate(StandardBasicTypes.INTEGER, "?1 % ?2"));
        registerFunction("substr", new StandardSQLFunction("substr", StandardBasicTypes.STRING));
        registerFunction("substring", new StandardSQLFunction("substr", StandardBasicTypes.STRING));
    }

    public boolean supportsIdentityColumns() {
        return true;
    }



    public boolean hasDataTypeInIdentityColumn() {
        return false;
    }


    public String getIdentityColumnString() {
        // return "integer primary key autoincrement";
        return "integer";
    }

    public String getIdentitySelectString() {
        return "select last_insert_rowid()";
    }

    @Override
    public boolean supportsLimit() {
        return true;
    }

    @Override
    protected String getLimitString(String query, boolean hasOffset) {
        return new StringBuffer(query.length() + 20).
                append(query).
                append(hasOffset ? " limit ? offset ?" : " limit ?").
                toString();
    }

    public boolean supportsTemporaryTables() {
        return true;
    }

    public String getCreateTemporaryTableString() {
        return "create temporary table if not exists";
    }

    public boolean dropTemporaryTableAfterUse() {
        return false;
    }

    @Override
    public boolean supportsCurrentTimestampSelection() {
        return true;
    }

    @Override
    public boolean isCurrentTimestampSelectStringCallable() {
        return false;
    }

    @Override
    public String getCurrentTimestampSelectString() {
        return "select current_timestamp";
    }

    @Override
    public boolean supportsUnionAll() {
        return true;
    }

    @Override
    public boolean hasAlterTable() {
        return false;
    }

    @Override
    public boolean dropConstraints() {
        return false;
    }

    @Override
    public String getAddColumnString() {
        return "add column";
    }

    @Override
    public String getForUpdateString() {
        return "";
    }

    @Override
    public boolean supportsOuterJoinForUpdate() {
        return false;
    }

    @Override
    public String getDropForeignKeyString() {
        throw new UnsupportedOperationException("No drop foreign key syntax supported by SQLiteDialect");
    }

    @Override
    public String getAddForeignKeyConstraintString(String constraintName,
                                                   String[] foreignKey,
                                                   String referencedTable,
                                                   String[] primaryKey,
                                                   boolean referencesPrimaryKey) {
        throw new UnsupportedOperationException("No add foreign key syntax supported by SQLiteDialect");
    }

    @Override
    public String getAddPrimaryKeyConstraintString(String constraintName) {
        throw new UnsupportedOperationException("No add primary key syntax supported by SQLiteDialect");
    }

    @Override
    public boolean supportsIfExistsBeforeTableName() {
        return true;
    }

    @Override
    public boolean supportsCascadeDelete() {
        return false;
    }

}